Circuit makers and breakers for signal or alarm circuits



J. 5. WHITE 2,704,814 CIRCUIT MAKERS AND BREAKERS FOR SIGNAL ORALARMCIRCUITS March 22, 1955 Filed July 23, 1951 I But" in;

Enventor Jesse 5 ruse WhiLE M fl fi attorney United States PatentCIRCUIT MAKERS AND BREAKERS FOR SIGNAL 0R ALARM CIRCUITS Jesse SpruceWhite, Miami Springs, Fla. Application July 23, 1951, Serial No. 238,113

2 Claims. (Cl. 307-132) This invention relates to circuit makers andbreakers particularly of a type for signal or alarm circuits.

A primary object of my invention is to provide combined switch mechanismwhich is responsive to complete a circuit responsive to conditionsprevailing at the location of the mechanism and to interrupt the circuitintermittently at said location whereby the curent is controlled so asto flow in intermittent impulses when the prevailing conditions are suchas to effect the closing of the circuit for transmitting such impulses.

Another object of my invention is to provide a control switch which isadapted for operation by thermal conditions or under the influence ofphysical conditions rendering the mechanism operative to transmit suchimpulses due to excessive temperatures for operating fire alarm orsignal systems or whereby the mechanism may be used in connection withburglar alarm systems.

Another object of my invention is to provide such a combined signalswitch mechanism which is inexpensive to construct and simple andeflicient in its operation.

Further objects and details of my invention will appear in the followingdescription supplemented by the accompanying drawings forming a part ofthis specification.

Referring to the drawings:

Fig. 1 is a side elevation view of a combined signal switch mechanism inaccordance with my invention.

Fig. 2 is a vertical sectional view thereof.

Fig. 3 is a fragmentary plan view thereof.

Fig. 4 is a vertical sectional view thereof taken substantially on theline 4-4 of Fig. 3.

Referring to the drawings, in general the switch mechanism in accordancewith my invention includes a rectangular casing of insulating materialprovided with transverse bores 11 for receiving bolts to hold front andback cover plates (not shown) thereon when desired. This casing houses acontrol switch A with an upwardly extending operating rod 12 and anintermittent circuit interrupter B.

As diagrammatically shown in Fig. 2 my switch mechanism is particularlyadapted for use in conjunction with a movable object C such as an objectwhich may rest thereon when the mechanism is mounted in a floor, or inconjunction with a door, window or the like so that the operating rod 12is depressed to maintain the circuit controlled by the mechanism open.

In Figures 3 and 4 my switch mechanism is shown in use with a fusiblesplit ring D which maintains the control switch A open wherein it isapplicable in a fire alarm system. Thus it will be seen that themechanism is adaptable for various uses though primarily intended forburglar or fire alarm systems.

In a preferred construction the casing 10 is formed with mounting bases13 and 13 for the respective control switch A and circuit interrupter B.Casing 10 has a bore hole 14 in its mounting base 13 through whichoperating rod 12 extends and a well 15 concentric therewith provides ahousing for a compression spring 16 which engages a disk-like collar 17to urge the rod to its upper circuit closing position as shown inFig. 1. Collar 17 is housed in a concentric opening 18 surrounding rod12 in the upper portion of casing 10 when the rod is depressed tocircuit opening position as shown in Figs. 2, 3 and 4 and this openingis provided with a groove 19 adjacent to the upper surface of casing 10into which the fusible split ring D may be inserted for retaining therod in its open circuit position when the mechanism Patented Mar, 22,1955 isk used in conjunction with a fire alarm system or the The lowerend of rod 12 carries a flexible metallic disk 20, a set screw 21 andlock washer 22 holding the same in place so that it will be carried toreciprocate between the circuit opening and closing positions of rod 12.This disk 20 provides the movable contact element of the control switchA which is reciprocable to engage and disengage from a pair of fixedcontacts 23 comprising set screws which also function as binding postsfor conductor leads. When the operating rod 12 is in circuit closedposition spring 16 urges it upward so that flexible disk 20 is broughtinto a tight engagement with the end surfaces of contacts 23, theflexibility thereof insuring good current conducting engagements withboth of them even though conductor leads of slightly different diametersor thicknesses may be employed.

While the circuit interrupter B may be of any desired type my preferredconstruction comprises a bimetallic thermal element 32 which is normallybowed downwardly and secured in place on mounting bases 13' of casing 10by set screws 24 which also provide binding posts for lead conductors. Acontact post 25 is positioned in a midpoint between the ends ofbimetallic strip 32 and has a silver plate 26 on its upper end whichelectrically engages the bimetallic thermal element under normaltemperature conditions. Contact post 25 has a collar 27 illustrated ashexagonal in shape at its base which engages the lower wall of casing10. A threaded extension 28 extends from collar 27 through a similarlythreaded opening through the casing 10 for receiving it and a nut 29thereon secures the contact post 28 in place. It is also provided with areduced threaded extension 30 carrying a nut 31 which provides a leadconductor binding It will be seen that set screws 23 and 24 and nut 31provide binding posts by means of which the control switch A and circuitinterrupter B may be connected as desired in a signal or alarm circuitof any well known type and they are adapted for operation in eitherdirect or alternating circuits. While no signal system or alarm circuitis illustrated conductor leads 33 and 34 for the control of such systemsby my control mechanism are illustrated as desirably connected with oneof the binding post set screws 23 and under the binding post nut 31 tocontact post 25. The control switch A and circuit interrupter B areconnected in series in such circuit by a conductor 35 extending from theother set screw binding post 23 to one of the set screw binding posts24.

In such a circuit it is clear that when control switch A is closed underchanged conditions-removal of object C, or fusing of ring D or thelike-current passing through the control switch A and interrupter B willheat interrupter strip 32 and cause it to bend to disengage its contactwith post 25, thus intermittently interrupting the current flow in thesignal or alarm circuit as long as the circuit is under the influencethereof.

It will be noted that the collar 17 normally resting on the bottom ofopening 18 closes the well 15 in which the spring 16 is disposed, thusisolating the spring with respect to the outside of the casing 10 toprevent the accumulation of foreign matter in the well. This is ofimportance when the mechanism is installed in the floor where dust anddirt settles by gravity and in the act of sweeping foreign matter may bemoved over the casing 10, some of it falling into the opening 18. Thenormal engagement of the collar 17 upon the bottom of opening 18 alsolimits the extent of movement of the rod 12 inwardly of the casing 10,so that the spring 16 cannot be compressed to the extent where theconvolutions of the spring touch one another and which might otherwisecause the spring to become permanently set in a fully compressedcondition, especially if subjected to consid erable heat. The collar 17also serves to somewhat insulate the spring from gas of hightemperature, such as would result from a fire, in the zone of the signalswitch mechanism. The arrangement is such that a fused ring D may bereplaced by a new one without gaining access to the main compartment ofthe casing 10.

I claim:

1. A signal switch mechanism including a rectangular casing ofinsulating material, mounting bases extending inwardly from wallsthereof, said casing having an opening therethrough between the ends ofone of said mountings and a concentric well in the outer portion thereofterminating at the outer wall with a further enlarged concentric recesshaving a groove in its circular wall adjacent to the surface of thecasing wall, a fusible split ring having its peripheral edges engaged insaid groove, a reciprocable rod extending through said opening having acollar thereon adapted to be seated in said enlarged concentric recessand to be retained in its seated position by the fusible split ringengaging the groove in the recess above the collar, a compression springin said concentric well for moving the rod outward upon the fusing orremoval of the split ring from the groove, a flexible metallic diaphragmcarried by the inner end of said movable rod, and set screws in saidmounting base adjacent to the ends thereof at opposite sides of saidreciprocable rod providing lead terminal binding posts and the headsthereof serving as contact members adapted to be engaged by the flexibledisk on said reciprocable rod when the rod is forced outwardly by saidcompression spring.

2. A signal switch mechanism including a rectangular casing ofinsulating material, mounting bases extending inwardly from wallsthereof, said casing having an opening therethrough between the ends ofone of said mountings and a concentric well in the outer portion thereofterminating at the outer wall with a further enlarged concentric recesshaving a groove in its circular wall adjacent to the surface of thecasing wall, a fusible split ring having its peripheral edges engaged insaid groove, a

reciprocable rod extending through said opening having a collar thereonadapted to be seated in said enlarged concentric recess and to beretained in its seated position by the fusible split ring engaging thegroove in the recess above the collar, a compression spring in saidconcentric well for moving the rod outward upon the fusing or removal ofthe split ring from the groove, a flexible metallic diaphragm carried bythe inner end of said movable rod, set screws in said mounting baseadjacent to the ends thereof at opposite sides of said reciprocable rodproviding lead terminal binding posts and the heads thereof serving ascontact members adapted to be engaged by the flexible disk on saidreciprocable rod when the rod is forced outwardly by said compressionspring, a bimetallic strip secured at its ends to a remaining pair ofsaid mounting bases projecting from a wall of the casing by means of setscrews which also function as conductor terminal binding posts, acontact post threadedly caried by the wall of the casing between saidmounting bases and extending inwardly and outwardly of the casing, asilver surface or plate on the inner end of said post against which saidbimetallic strip lies in electrical contact engagement when said controlswitch circuit closing diaphragm is out of engagement with said contactmembers thereof, and a lead terminal binding post on the outer end ofsaid contact post.

References Cited in the file of this patent UNITED STATES PATENTS527,375 Rowand Oct. 9, 1894 606,076 Ovenden June 21, 1898 1,095,382Clorius et a1. May 5, 1914 1,159,602 Scheuer Nov. 9, 1915 1,182,283 LutzMay 9, 1916 1,494,335 Boston May 20, 1924 1,785,366 Shoenberg Dec. 16,1930 2,029,097 Garner Jan. 28, 1936 2,276,428 Soreng Mar. 17, 19422,439,502 Tate Apr. 13, 1948

